Why? You have a choice over sitting next to someone who is not fussed or someone who may be uncomfortable or have good reason to have their bag on the seat, and you go for the one that causes the mist unhappiness?

Well you might be that's ok because you have no way of knowing, if someone has put their bags there it is a signal that might have those reasons so rather than seek these people out assuming they are selfish just don't assume anything and just sit somewhere else.

yeah of course it is, people often use bags to signal 'please sit somewhere else' most of the time they will not have a good reason for this, but you don't know there reason and sometimes it will be totally valid. given your original post suggests there are other seats, just sit in the other seats why risk it? what benefit is there in pissing someone off, especially if they do have a good reason for it?

in addition to disability (both as a keeping people away strategy or simple difficulty moving the bags) there are lots of reasons; perhaps you have valuables you want to keep an eye on, perhaps you have been beaten up or harassed in a similar situation before and want to keep people away. but really even having a mild preference to not have someone sit next to you is a good enough reason if there are plenty of other free seats.

i always put my bags down in order to occupy space because i'm disabled and more often than not already uncomfortable enough as it is sitting in the seats. i do not want someone sitting next to me for reasons of pain, comfort and stress/anxiety, especially if they just swing their legs out to the aisle when i need to get off and don't give me enough space and i end up so much worse off.

you're the one who has created this very specific strange scenario..
frankly the bag person should feel lucky that its me sitting next to them and not the other people getting on the bus at the next stop

So what was your go for the one with the bag next to them on the seat :) comment? To me that implies singling out someone who doesn't want you there and the smiley indicates taking pleasure in, together implies you think they deserve it.

Im helping them, saving them from the other bus wankers.
Im not one of these people who sit with their legs well apart (despite being well endowed), I don't listen to annoyingly loud music, I don't just swivel to let you get out.
You're lucky its me who is sitting next to you, Im happy to help you.

It's completely beyond me why a person over the age of about 25 would ever have to get on a bus or a train. Why wouldn't you just drive, or if you didn't drive but you're a grown-up on a grown-up's salary, get a taxi? Self-respect and personal space is more important, surely.

I hate people who leave their bags on the seat when the bus is clearly filling up, they should be shot or thrown out of the top deck. But if the are plenty of seats who gives a shit. It's bad etiquette to sit next to tall people before shorter people

usually female, legs together, all over to one side, looking out of the window. They are basically saying "I will keep to my side". I return the favour by keeping over to my side. Failing that, the weediest looking bloke. Next option is people with bags next to them, they obviously don't want anyone there for various reasons (I do this also), but they can move if needed. After that, hard looking blokes with their legs spread taking up room, then crazy tramps, then gangs of teenage twats.

A man of about 50 or so was absolutely hammered and despite sitting next to the train toilet, got up and threw up in the bins by the doors (you know the little tiny ones that are always overflowing) his head was right in it amongst all the rotting banana peels and that. Fucking state. It wasn't even nine o'clock on a fucking Tuesday. Grim.

it's warm enough to cycle to work again (or at least the roads are less icy / dangerous) = no more buses for me until December.

There is a definite pecking order which will be different for everyone to an extent. Number 1 is 'need' - if you need to sit down you'll sit next to anyone. If you are picking and choosing my choice is made the further I walk down the bus thinking generally I should have sat down already. When on the inside practically no one says excuse me when they get up, they just barge past. Packed buses are soul destroying experiences.

i just sit in the best located seat ie the nearest, or the upstairs front of the bus, or the seat that's not a priority seat, or the one that's easiest to get off the vehicle from or the one that allows me space for what im carrying

One night I was taking the bus home slightly 'refreshed' when this insanely hot girl came on and sat right next to me, even though there were tons of free seats elsewhere with no one sitting on them.

This kind of behaviour truly plays havoc with the male mind...

She probably gave no thought to it whatsoever, simply sat on the first seat she saw after climbing up the stairs, whereas I sat there contemplating my life and considering whether or not I would be able to leave my partner and kids for this person, a decision which would seriously affect the rest of my days.

Next to: someone who isn't huge, and who can play Candy Crush without having to have their elbows by their side.
Opposite: someone who knows how to sit up straight and doesn't put their bag on the floor.

If I'm in the mood for annoying then target number one will be anyone with their feet on the seat, followed by anyone with a pet bag next to them.

A while back a "bag on the seat" situation escalated down the carriage from me. The only thing I recall hearing during the hilarious row was when the bloke trying to sit down shouted, in a heavy Northern Irish accent "This seat isn't for a bag. It's for an ARSE!" which was funny on a couple of levels.

should there be better provision on trains / buses for people that (for whatever reason) need a bit of extra space? I know that there are "priority seats" on most trains for people with reduced mobility, and usually there is a carriage or two suitable for a wheelchair user, but is this enough? No idea how many people would benefit from improved provision, or would be put off from travelling on public transport because of the conditions.

Personally I wouldn't ask someone to move their bag unless there were no other seats, but if there was no choice I'd usually ask if I could sit there.

usually one person sits on either side, then someone sits in the middle. Few people try and sit cramped up making it a fivesome even on packed buses. It can backfire though, getting out can be a bastard then.